Synthesis and characterization of gold nanoshells using poly(diallyldimethyl ammonium chloride)

Metal nanoshells are a new class of nanoparticles consisting of dielectric cores with metal shells. In this investigation, a novel linker, polydiallyldimethyl ammonium chloride (PDADMAC), was used for formation of gold nanoshells on the surface of silica nanoparticles. In comparison with commonly used linker 3-aminopropyltrimethoxysilane (APTMS) at a given amount, this linker shows much better coverage in both nucleation and shell growth stages of nanogold shell formation. Furthermore, the concentration of PDADMAC can be varied over a wider range, without causing system collapse while fine tuning shell coverage. It was also observed that the size of gold nanoparticles strongly influences the extent to which they attach themselves to the surface of silica nanoparticles.